// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "main.h"

#include <Eigen/CXX11/Tensor>

using Eigen::Tensor;

template<int DataLayout>
static void
test_simple_padding()
{
	Tensor<float, 4, DataLayout> tensor(2, 3, 5, 7);
	tensor.setRandom();

	array<std::pair<ptrdiff_t, ptrdiff_t>, 4> paddings;
	paddings[0] = std::make_pair(0, 0);
	paddings[1] = std::make_pair(2, 1);
	paddings[2] = std::make_pair(3, 4);
	paddings[3] = std::make_pair(0, 0);

	Tensor<float, 4, DataLayout> padded;
	padded = tensor.pad(paddings);

	VERIFY_IS_EQUAL(padded.dimension(0), 2 + 0);
	VERIFY_IS_EQUAL(padded.dimension(1), 3 + 3);
	VERIFY_IS_EQUAL(padded.dimension(2), 5 + 7);
	VERIFY_IS_EQUAL(padded.dimension(3), 7 + 0);

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 6; ++j) {
			for (int k = 0; k < 12; ++k) {
				for (int l = 0; l < 7; ++l) {
					if (j >= 2 && j < 5 && k >= 3 && k < 8) {
						VERIFY_IS_EQUAL(padded(i, j, k, l), tensor(i, j - 2, k - 3, l));
					} else {
						VERIFY_IS_EQUAL(padded(i, j, k, l), 0.0f);
					}
				}
			}
		}
	}
}

template<int DataLayout>
static void
test_padded_expr()
{
	Tensor<float, 4, DataLayout> tensor(2, 3, 5, 7);
	tensor.setRandom();

	array<std::pair<ptrdiff_t, ptrdiff_t>, 4> paddings;
	paddings[0] = std::make_pair(0, 0);
	paddings[1] = std::make_pair(2, 1);
	paddings[2] = std::make_pair(3, 4);
	paddings[3] = std::make_pair(0, 0);

	Eigen::DSizes<ptrdiff_t, 2> reshape_dims;
	reshape_dims[0] = 12;
	reshape_dims[1] = 84;

	Tensor<float, 2, DataLayout> result;
	result = tensor.pad(paddings).reshape(reshape_dims);

	for (int i = 0; i < 2; ++i) {
		for (int j = 0; j < 6; ++j) {
			for (int k = 0; k < 12; ++k) {
				for (int l = 0; l < 7; ++l) {
					const float result_value =
						DataLayout == ColMajor ? result(i + 2 * j, k + 12 * l) : result(j + 6 * i, l + 7 * k);
					if (j >= 2 && j < 5 && k >= 3 && k < 8) {
						VERIFY_IS_EQUAL(result_value, tensor(i, j - 2, k - 3, l));
					} else {
						VERIFY_IS_EQUAL(result_value, 0.0f);
					}
				}
			}
		}
	}
}

EIGEN_DECLARE_TEST(cxx11_tensor_padding)
{
	CALL_SUBTEST(test_simple_padding<ColMajor>());
	CALL_SUBTEST(test_simple_padding<RowMajor>());
	CALL_SUBTEST(test_padded_expr<ColMajor>());
	CALL_SUBTEST(test_padded_expr<RowMajor>());
}
